Piston-type machine with conrod-free mechanism

ABSTRACT

The present invention pertains to the field of piston machines, mainly those that include a mechanism without any connecting rod for converting the reciprocating movement of the pistons into a rotating movement of the output shaft. This invention essentially relates to a piston machine that includes a mechanism without any connecting rod and that comprises the following members: a body ( 1 ) with a plurality of cylinders ( 2 ); a plurality of pistons ( 5 ) with piston rods ( 6 ); sliding members ( 13 ) formed on the rods ( 6 ); a plurality of guides for the sliding members ( 13 ), each connected to the body ( 1 ) and capable of displacing the corresponding sliding member ( 13 ) along the axis of the corresponding cylinder ( 2 ); two coaxial cranked shafts ( 7 ) mounted in the body ( 1 ); and a crankshaft ( 10 ) mounted between the cranked shafts ( 7 ) and having its main journals ( 11 ) connected to said cranked shafts ( 7 ) while the rod journals ( 12 ) are connected to the corresponding piston rods ( 6 ). This machine is characterised in that each guide is made in the form of an annular member ( 14 ) comprising guiding surfaces ( 15 ). Each annular member ( 14 ) is mounted in the body ( 1 ) so as to be coaxial relative to the cranked shafts ( 7 ) and so as to be capable of rotation about the axes ( 16 ) of said cranked shafts ( 7 ), and also comprises means for fixing its position relative to the body ( 1 ). This structure ensures the automatic adjustment of the sliding member ( 13 ) guides into an optimal position relative to the axes of the corresponding cylinders ( 2 ) during the engine assembly, which prevents engine seizure.

FIELD OF INVENTION

The invention relates to piston-type machines, and particularly tomachines provided with a conrod-free mechanism intended for transformingthe translational motion of pistons to the rotary motion of an outputshaft.

The term “conrod” as used herein means “connecting rod”.

Hereinafter the term “machine” means a device that is capable ofperforming functions of both an engine and a pump. The term “engine”means a device intended for transforming the energy of a working fluidto the mechanical energy, and particularly internal combustion engines,steam engines, hydraulic engines etc. The term “pump” means a deviceintended for forcing or compressing fluids by mechanical means, andparticularly both pumps for fluids and compressors for forcingcompressible media, i.e. gases or vapors.

The inventive solution relates to a piston-type machine in the generalmeaning thereof, and may be used both in engines and in pumps.

BACKGROUND OF THE INVENTION

Well-known in the art is the kinematic layout of the slider-crankmechanism, implementing a conrod-free mechanism intended fortransforming the translational motion of pistons to the rotary motion ofan output shaft. The layout comprises a housing member provided with twocylinders with mutually perpendicular axes; pistons with piston rods;sliders provided on piston rods; slider guide members; a carrier member,and an intermediate member engaged in rotary pairs with rods and withthe carrier member.

In the course of reciprocal motion of pistons, the intermediate memberpivotally connected to cylinder rods and the carrier member, carries outa complicated plane-parallel motion, thereby providing relationshipbetween the motion of pistons and the rotation of the carrier member,with transformation of the reciprocal motion of pistons to the rotarymotion of the carrier member without the use of connecting rods.

The above kinematic layout serves as a base for development of aconrod-free internal combustion engine known as “Balandin engine” (S. S.Balandin, Conrod-free Internal Combustion Engines, Moscow,Mashinostroyenie, 1968, pp.14-15). This engine comprises a housingmember provided with cylinders; pistons with piston rods; slidersprovided on piston rods; slider guide members each being connected tothe housing member and made for displacing a corresponding slider alongthe axis of a corresponding cylinder; two coaxial carrier membersmounted inside the housing member, and a crankshaft disposed between thecarrier members, main journals of the above crankshaft being pivotallyconnected to carrier members, and rod pins, to relevant piston rods.

In the course of reciprocal motion of pistons, the crankshaft that ispivotally connected to cylinder rods and carrier members, carries out acomplicated planetary motion by rotating around its own axis and theaxis of carrier members, and provides the relationship between thereciprocal motion of the pistons and the rotation of the carriermembers, with transformation of the reciprocal motion of pistons to thesynchronous rotary motion of the carrier members without the use ofconnecting rods. Here, the main journals of the crankshaft are movingalong a circle with a radius equal to ¼ stroke of the pistons, whilepistons and rods connected to the rod pins of the crankshaft arecarrying out only.the rectilinear reciprocal motion along the stroke ofpistons, without exerting any lateral thrust against cylinder walls.This mechanism may be used not only for internal combustion engines, butalso for driven compressors, pumps, piston gas generators, and otherpiston-type machines. The engine with a similar kinematic layout is alsodescribed in SU, A1, 118471.

In the course of practical implementation of the above devices, thereoccurs the problem of design of guide members that would permit, whenassembling the engine, to adjust these guide members to a positionensuring a coordinated motion of pistons inside cylinders andsliders/rods in the guide members without any distortions and jamming ofthe mechanism. This problem acquires a critical importance from thestandpoint of the technological effectiveness of assembling of a pistonmachine, particularly a multicylinder piston machine.

Also known in the art is a piston-type machine disclosed in thespecification to SU, A1, 1216271. This machine comprises a housingmember provided with cylinders and having an axial hole; liners mountedinside the cylinders; pistons with piston rods, disposed inside theliners; sliders provided on piston rods; slider guide members eachprovided for displacement of a corresponding slider along the axis of acorresponding cylinder; two coaxial carrier members mounted inside thehousing member, and a crankshaft disposed inside the axial hole of thehousing member between the carrier members, main journals of the abovecrankshaft being connected to carrier members, and rod pins, withrelevant piston rods. Slider guide members are made integrally with theliners and constitute an extension of the internal surface of the liner.That is, each of the guiding surfaces for a corresponding slidecomprises a structural member of a corresponding liner, in which theguiding surface for the slider constitutes an extension of the internalsurface of the liner.

The reciprocal motion of pistons in this known piston-type machine istransformed, through the rods with sliders moving within guide members,to the planetary rotary motion of the crankshaft that is pivotallyconnected to the rods and carrier members. The planetary motion of thecrankshaft causes synchronous rotary motion of the carrier members.During machine operation in the engine mode, the power may be picked upfrom any carrier member or from an additional shaft being in kinematicrelationship with the carrier members and providing synchronization ofthe rotary motion of the carrier members.

In this case, guide members for sliders are made non-adjustable. Theaccuracy of location of the guiding surfaces is ensured in the processof liner manufacture, since the slider guide members are made integralwith the liners, constitute the extension of the liner internal surface,and are made in a single run.

However, in this embodiment of the piston-type machine the distancebetween the guiding surfaces restricting the displacement of each slidershould not exceed the diameter of liners since the guiding surfaces ofsliders constitute the extension of the liners internal surfacescomprising guiding surfaces for the pistons. From this, it follows thatin the above design which inevitably provides the planetary motion ofthe crankshaft within the limits of the distance between the guidingsurfaces of sliders, there exist restrictions for the eccentricity of acrankshaft, and hence for the stroke length of each piston. Thiscircumstance substantially restricts the possibilities of using theabove design in piston-type machines since it does not permit to providea required ratio between the cylinder.diameter and the value of pistonstroke length. It is of special importance in the designs of internalcombustion engines, and particularly in diesel engines.

Known in the prior art are designs of piston-type machines provided withadjustable guide members of piston rods. Thus, known in the art is acrank mechanism of a piston type machine, disclosed in SU, A1, 1513259.This mechanism comprises a housing member with a cylinder; a piston witha piston rod; a slider provided on the piston rod; a slider guide memberconnected to the housing member and provided for slider displacementalong the cylinder axis; a carrier member; and a con-rod pivotallyconnected to the slider and to the journal of the carrier member.Naturally, in a multipiston machine the above crank mechanism isrepeated for each piston group. The slider guide member is shaped as aplatelet mounted on the housing member for displacement and fixation ina selected position by means of screws and nuts. Suspended from thisplatelet by means of bolts and disk springs is a clamp member providedwith solids of revolution. The solids of revolution are mounted on theclamp member for interaction with flat contact surfaces provided on theslider.

In this mechanism, the reciprocal motion of the piston is transformed tothe rotary motion of the crankshaft via the rod provided with a sliderthat is moving in the guide member, and then via the con-rod. Here, flatcontact surfaces of the slider interact with the solids of revolutionthat are fastened to the clamp member, transmitting the forces createdthereby via disk springs and platelet to the housing member. In case ofa need to adjust the position of a guide member, the platelet is movedby means of screws to a required position with respect to the housingmember, following which the platelet is fixed in the selected positionby means of nuts.

In the above design, the procedure of setting the guide members supposesmanual adjustment of each guide member to the required position withrespect to the axes of relevant cylinders and contact surfaces ofsliders; therefore, under real conditions of assembling a piston-typemachine it is practically impossible to attain a required accuracy ofsetting all the guide members to prevent jamming of the mechanism. Inaddition, the presence of console components and threaded joints in thepower chain of the guide member restricts the use of the guide memberunder consideration under conditions of high dynamic loads, particularlyin internal combustion engines, and especially in diesel engines.

Known in the art are practical designs of conrod-free internalcombustion engines constructed in accordance with the “Baiandin design”.(S. S. Balandin, Conrod-free Internal Combustion Engines, Moscow,Mashinostroyenie, 1968, pp.28-75). These include a four-cylinder enginedeveloped for the purpose of testing major kinematic and designproperties of the conrod-free layout and performance of the conrod-freepower mechanism in the engine system under actual loads, as well asstandardized conrod-free engines having 140 to 400 hp power rating. Page39 of this book contains the description of a four-cylinder, four-strokegasoline engine of the aircraft type. This known engine comprises ahousing member provided with cylinders, a front portion, a mediumportion, and a back lid. The front portion accommodates the carriermember of a conrod-free mechanism, transmitting the engine power to aconsumer, and a gas distribution mechanism. Mounted in the back lid isanother carrier member of the conrod-free mechanism. The medium portionaccomodates, between carrier members, a crankshaft with rods of theconrod-free mechanism. Main (extreme) journals of the crankshaft areconnected to carrier members, and rod pins, to relevant piston rods.Each rod is provided with a slider that is mounted in guide members.Each guide member is connected to the housing member and is made fordisplacing a relevant slider along the axis of a corresponding cylinder.All the parts of the engine are connected therebetween by studs. Guidemembers for each slider are made as two separate segments, each segmentbeing provided with a guiding surface and fastened to the housing memberby means of bolted joints so that the guiding surfaces of the abovesegments, when being situated in parallel, form a guiding structure thatensures the motion of a corresponding slider along the axis of arelevant cylinder. Adjustment of guide members and provision of accuracyof such adjustment are carried out by hand, in the process ofassembling, by fitting each segment to corresponding contact surfaces ofsliders in a certain position, followed by fastening of segments to thehousing member by means of bolted joints.

During the working cycle, each piston carries out reciprocating motionwithin a corresponding cylinder. Piston rods are moving together withpistons; in so doing, rod sliders are moving in the guide membersthrough which they transfer resulting lateral loads to the housingmember. Piston rods, being in the pivoted joint with the crankshaft, putit in the planetary motion during which the crankshaft rotates aroundits axis and around the axis of carrier members, thereby putting in therotary motion the carrier members; each of these carrier members can bethe output shaft of the engine.

The above design is complicated to assemble since it is required to fiteach guiding segment, thereby ensuring the parallel arrangement of theguiding surfaces of segments and their orientation relative to the axesof corresponding cylinders. Precise adjustment of all the guidingsegments, minimizing the probability of mechanism jamming, in thisembodiment is extremely difficult and under real conditions ofassembling a piston-type machine with conrod-free mechanism ispractically unattainable.

BRIEF DESCRIPTION OF THE INVENTION

The invention is based upon the object to develop an improvedpiston-type machine with conrod-free mechanism, in which design featureswould provide the possibility of self-adjustment of slider guide membersto an optimal position relative to axes of corresponding cylinders inthe course of assembling, thereby reducing the probability of jamming ofthe mechanism, improving the technological effectiveness of theresulting device, and substantially simplifying the assembling process.

The object set forth is attained in that in a piston-type machine withconrod-free mechanism, comprising a housing member provided withcylinders; pistons with piston rods; sliders provided on piston rods;slider guide members each being connected to the housing member and madefor displacing a corresponding slider along the axis of a correspondingcylinder; two coaxial carrier members mounted inside the housing member,and a crankshaft disposed between the carrier members, main journals ofthe above crankshaft being pivotally connected to carrier members, androd pins, to relevant piston rods, according to the invention, eachguide member is made as a ring-shaped member with guiding surfaces, eachring-shaped member being mounted within, the housing member in coaxialrelationship with carrier members for rotating around the axis of saidcarrier members, and provided with means for fixing position thereofrelative to the housing member.

In the preferred embodiment of the invention, the guiding surfaces oneach ring-shaped member may be formed by parallel surfaces of a grooveprovided in the diametral direction on one of the side surfaces of thering-shaped member for displacement of the slider along said groove.

The means for fixing each ring-shaped member relative to the housingmember are expedient to be provided as a screw joint, wherein a threadedhole is disposed in the ring-shaped member and the screw is mounted in acorresponding hole provided in the housing member, the diameter of saidhole exceeding the diameter of said screw by 1.02 to 1.2 times.

In addition, it is also expedient to provide the means for fixing eachring-shaped member as a screw joint, wherein said threaded hole isdisposed in the housing member and the screw is mounted in a holeprovided in the ring-shaped member, the diameter of said hole exceedingthe diameter of said screw by 1.02 to 1.2 times.

Providing slider guide members as ring-shaped elements, mounting thering-shaped members within the housing member in coaxial relationshipwith carrier members for rotation around the axis of carrier members,and fixing position thereof relative to the housing member ensures thepossibility of self-adjustment of the slider guide members relative tothe axes of corresponding cylinders. In the process of assembling theinventive machine, the mounting of carrier members, crankshaft, pistonswith piston rods, and slider guide members is followed by the motoringof the mechanism, during which the ring-shaped guide members, whilerotating in mounting seats thereof around the axis of carrier members,independently occupy the most optimal position to prevent the jamming ofthe mechanism, following which they are fastened inside the housingmember with the use of available means for fixing.

BRIEF DESCRIPTION OF DRAWINGS

The inventive piston-type machine with conrod-free mechanism is furtherdescribed in more detail and with reference to the accompanyingdrawings, in which:

FIG. 1 is a general view of the inventive piston-type machine withconrod-free mehanism, cross-section.

FIG. 2 is section II—II of the piston-type machine with conrod-freemechanism, shown in FIG. 1.

FIG. 3 is section III—III of the piston-type machine with conrod-freemechanism, shown in FIG. 1.

FIG. 4 is a three-dimensional view of the piston group.

FIG. 5 is an embodiment of the means for fixing guide members.

FIG. 6 is section VI—VI of the piston-type machine with conrod-freemechanism, shown in FIG. 1.

BEST EMBODIMENT OF THE INVENTION

As it is shown in FIGS. 1 through 4, the inventive piston-type machinewith conrod-free mechanism comprises housing member 1 provided withcylinders 2, tunnel hole 3 and flange cover 4, and pistons 5 providedwith piston rods 6. Carrier members 7 are coaxially mounted insidehousing member 1. Carrier members 7 have bearings 8 and eccentric holes9. Disposed between carrier members 7 is crankshaft 10 whose crankshaftjournals 11 are pivotally connected to carrier members 7 while bearings12 are pivotally connected to corresponding piston rods 6 via sliders 13provided on piston rods 6. Each of sliders 13 is mounted in a guidemember made in the form of ring-shaped member 14 providing with guidingsurfaces 15 made for displacing a corresponding slider 13 along the axisof a corresponding cylinder 2. Each ring-shaped member 14 is connectedto housing member 1 for rotation thereof around axis 16 of carriermembers 7 and is provided with means for fixing position thereofrelative to housing member 1. Guiding surfaces 15 on ring-shaped member14 are made in the form of a groove disposed diametrically on one of thesides of ring-shaped member 14 for displacement of slider 13 also saidgroove. Means for fixing each ring-shaped member 14 relative to housingmember 1 are made in the form of a screw joint wherein threaded hole ismade in ring-shaped member 14 and screw 18 is mounted in hole 19provided in housing member 1 whose diameter exceeds the diameter ofscrew 18 by 1.02 to 1.2 times. Also possible is the embodiment of thescrew joint where in ring-shaped member 14 are provided with flanges 20(FIG. 5) having holes 21 for mounting screws 18, and threaded holes 22are made in housing member 1. Carrier members 7 are provided with gearrings 23, 24 that are in engagement with pinions 25, 26. Pinions 25, 26are connected to synchronizing shaft 27 (FIG. 6). The presence ofsynchronizing shaft 27 in the machine design ensures synchronousrotation of carrier members 7 and prevents jamming of crankshaft 10 inits pivoted joints with carrier members 7. Piston rods 6 are connectedto sliders 13 by means of threaded joint 28.

The procedure used for assembling the piston-type machine is as follows.Each of sliders 13 is mounted between guiding surfaces 15 of ring-shapedmembers 14. Crankshaft 10 is placed in the hole of one slider and thefirst of carrier members 7 is mounted so as to ensure location ofbearing 8 of carrier member 7 within the mounting seat of ring-shapedmember 4, and crankshaft journal 11 of crankshaft 10, inside eccentrichole 9 of carrier member 7. Following this, successively disposed oncrankshaft 10 are other sliders 13 in assembly with ring-shaped member14 serving as guides. Then the second carrier member 7 is mounted withthe use of the same rules of assembling as those used for mounting thefirst carrier member 7. Sliders 13 are disposed within guiding surfaces15 so that they do not protrude beyond the limits of the maximumdiameter of ring-shaped member 14. The thus assembled parts are mountedinto tunnel hole 3 in housing member 1. In so doing, ring-shaped members14 are disposed in corresponding mounting seats provided in housingmember 1, for rotation around axis 16 of carrier members 7. After this,flange cover 4 is mounted. Screws 18 are mounted into threaded holes 19or 22 (second option) without tightening. Sliders 13 are connected topiston rods 6 by means of threaded joint 28. Then synchronizing shaft 27is mounted so that pinion 25, 26 come into engagement with gear rings23, 24 of carrier members 7. Following this, the motoring of themechanism is carried out, during which ring-shaped guide member 14,being the guide of sliders 13, are self-adjusted and occupy the optimalposition relative to the axes of cylinders 2, wherein the probability ofjamming of the mechanism is minimal. Position of ring-shaped member 13is fixed by tightening screws 18. The mechanism is ready for operation.mounting seat of ring-shaped member 4, and main journal 11 of crankshaft10, inside eccentric hole 9 of carrier member 7. Following this,successively disposed on crankshaft 10 are other sliders 13 in assemblywith ring-shaped members 14 serving as guides. Then the second carriermember 7 is mounted with the use of the same rules of assembling asthose used for mounting the first carrier member 7. Sliders 13 aredisposed within guiding surfaces 15 so that they do not protrude beyondthe limits of the maximum diameter of ring-shaped members 14. The thusassembled parts are mounted into tunnel hole 3 in housing member 1. Inso doing, ring-shaped members 14 are disposed in corresponding mountingseats provided in housing member 1, for rotation around axis 16 ofcarrier members 7. After this, flange cover 4 is mounted. Screws 18 aremounted into threaded holes 19 or 22 (second option) without tightening.Sliders 13 are connected to piston rods 6 by means of threaded joint 28.Then synchronizing shaft 27 is mounted so that pinions 25, 26 come intoengagement with gear rings 23, 24 of carrier members 7. Following this,the motoring of the mechanism is carried out, during which ring-shapedguide members 14, being the guide of sliders 13, are self-adjusted andoccupy the optimal position relative to the axes of cylinders 2, whereinthe probability of jamming of the mechanism is minimal. Position ofring-shaped members 13 is fixed by tightening screws 18. The mechanismis ready for operation.

The piston-type machine a conrod-free mechanism operates as follows.

During the working cycle, each piston 5 carries out reciprocating motionwithin a corresponding cylinder 2. Piston rods 6 provided with sliders13 are moving together with pistons 5; in so doing, sliders 13 of pistonrods 6 are moving between guiding surfaces 15 of ring-shaped members 14through which they transfer resulting lateral loads to housing member 1.Piston rods 6, being in the pivoted joint with crankshaft 10, put it inthe planetary motion during which crankshaft 10 rotates around its axisand around axis 16 of carrier members 7, thereby putting in the rotarymotion carrier members 7. Synchronization of the rotation of carriermembers 7 is carried out by means of synchronizing shaft 27 connected topinions 25, 26 that are in engagement with gear rings 23, 24 of carriermembers 7. Engine power may be picked up from any carrier member 7 orfrom synchronizing shaft 27. During operation of the piston-type machinein the engine mode, the energy of working fluid supplied to cylinders 2is transformed to mechanical energy. During operation of the piston-typemachine in the pump or compressor mode, forced rotation of carriermembers 7 results in injection or compression of fluids by pistongroups.

The inventive piston type machine with conrod-free mechanism ischaracterized by a high technological effectiveness of design and simpleprocedure of assembling during which slider guide members occupy anoptimal position due to their self-adjustment relative to the axes ofcorresponding cylinders, which fact permits to minimize the probabilityof mechanism jamming in the operating mode.

INDUSTRIAL APPLICABILITY

The proposed mechanism may be used in a variety of piston-type machinesthat require high load capacity, high mechanical efficiency, goodbalance (minimum vibrations), and compactness. First of all, suchmachines include automotive and aircraft piston-type engines, andparticularly diesel engines, marine and locomotive diesels, engines offarming, construction, and other kinds of machinery.

What is claimed is:
 1. A piston-type machine comprising: a housingmember provided with cylinders; pistons with piston rods operativelyassociated with said cylinders; sliders provided on said piston rods;slider guide members, each being connected to said housing member, forguiding a corresponding one of said sliders along an axis of acorresponding cylinder; two coaxial carrier members mounted inside saidhousing member; a crankshaft disposed between said carrier members;first bearings of said crankshaft being connected to said carriermembers; second bearings being connected to corresponding piston rodpins; each said guide member comprises a ring-shaped member with guidingsurfaces; each said ring-shaped member being mounted within said housingmember in coaxial relationship with said carrier members for rotatingaround an axis of said carrier members; fixing means for fixing theposition of said ring-shaped members relative to said housing members;said fixing means for fixing each said ring-shaped member relative tosaid housing member comprises a screw joint having a threaded holeprovided in said housing member and a screw mounted in a second holeprovided in said ring-shaped member; and said second hole having adiameter which exceeds the diameter of said screw by 1.02 to 1.2 times.